Various forms of cannula or needle covers have been employed to this date. Some of these involve simple closed or open end rubber tubes encircling the cannula; sealed glass tubes which are breakable; molded tubular elements encircling the cannula and extending beyond the free end and molded plastic tubes which are integrally joined to the supporting structure or hub surrounding the anterior end of said cannula. While certain of these are adequate for their particular needs, they fail to cover all of the functions required under certain circumstances, namely, the maintenance of aseptic conditions surrounding a cannula that is to be utilized for intravenous injections, intermuscular injections or any other subcutaneous injections administered to patients. Additionally, when such covers are utilized with cannulas attached to a medicament source, it is virtually impossible to insure that they have not been tampered with, i.e., the contents of the medicament container withdrawn and replaced by a secondary undesirable material. Attempts have been made to seal the ends of such cannula covers or to embed the sharpened distal end of the cannula in soft material. One of the major problems in the previous attempts has been the presence of particles of the cover material being found in the lumen of the cannula which either blocks the flow of medicament or, alternatively, can be devastatingly injurious to the patient's health if such particles become introduced into the bloodstream after penetration by the sharpened end of the cannula.